It depends on the kind of Website you're talking about. If it's just a business-to-consumer site where you're selling products then you take the total conversions on a page, subtract out non-search conversions, and whatever is left are the search conversions.

Since the major search engines are no longer providing complete referral data you either live without keyword attribution or you use the Webmaster dashboard data that Bing and Google publish to estimate percentages of conversions by keyword.

You can refine your estimates by changing the page so that it gets more traffic for one query or less traffic for a query; if you see corresponding changes in conversions then that's a pretty good sign that you are tweaking a query tied to the conversions.

Remember to distinguish between internal search and external search. If you have a good internal search tool you'll have the query data you need (for internal/site search) to measure keyword conversion.

I suppose you could do the same for a B2B site although I think you're more likely to see people poke around the site before making a purchase decision. It may take more effort to extract the search-driven traffic (or you'll have to compromise with yourself on what you mean by "search-driven traffic").

New to the forum and I have a question about calculating SEO ROI/Revenue.

How do you guys actually calculate the ROI/Revenue of SEO efforts? Especially for non-branded keywords. And could you give me an example of such calculation.

Thank you in advance

First you have your cost of total SEO work done e.g. $500 or something.

Then over on your Analytics account you'll see precisely how many leads this work has earned you in let's say the last month. For a nice round figure we'll say 500 visitors.

This lands them straight on your homepage with a 50% bounce rate from this traffic source. So you now have 250 visitors navigate to other pages in your site.

With a very basic site, you may have a contact form for leads to get in touch.

So let's say you have a 3% conversion rate.

250 / 100 * 3 = 7.5 contacts. Let's round this down to 7.

Your next job is your sales team, who are like God's gift to the world (for example right!) and convert every single lead.

Each lead, is worth on average of $1000.00 to your business and you've sold all 7 of those visitors.

Revenue: $7000.00

Profit: $6500.00

Now of course, this is oversimplified, and you'll lose visitors at various points on your site.

People pay a lot of money for people to figure out this kind of thing because it can be extremely complicated depending on the size of your website, the funnels etc. There are various ways to do it, it's always going to revolve around the numbers. Your conversion rates at various points are going to be your best friend for figuring out the ROI of an SEO campaign.